From the racetrack to public streets

Cover Story

From the racetrack to public streets

Automakers test components, systems, materials, and technologies on the track to hone performance before adding new options to passenger vehicles.

Robert Schoenberger

1983 Porsche 956, the first racecar to use a dual-clutch transmission.

By 2022, Porsche expects to invest $7.4 billion in electric powertrains for future vehicles. Those initiatives started on the racetrack with the Porsche 919 hybrid sports car, a vehicle that won two 24 Hours of Le Mans races.

“The possibilities and performance of electric cars have been a central topic at Porsche for quite a while,” says Andreas Seidl, head of technical development for Porsche’s electrified racing cars. “The deeper our engineers get into the topic, the more fascinating the solutions become.”

To test those ideas, Porsche is heading back to the track, joining the Formula E electric car race series for the 2019 season. Entering that race series will coincide with the first product launch of the automaker’s Mission E initiative to produce high-powered electric cars for luxury buyers.

It’s a pattern the auto industry has experienced throughout its entire existence – test new ideas and technologies on the track, the most brutal environment for performance, before bringing new technologies to the mass market. Obvious examples include engine technologies such as dual-overhead cam layouts, superchargers, and turbochargers. But the quest for power is a tiny part of racing’s impact on the mass market.

1981 McLaren MP4/1, the first racecar with a carbon fiber reinforced plastic (CFRP) chassis and monocoque.

Transmissions

Two popular transmission types owe a lot to racing. Dual-clutch transmissions (DCT) were effectively born out of Formula 1 racing, and continuously variable transmissions (CVT) were in low-volume development for passenger vehicles when a race team demonstrated their potential.

DCT – Invented in the 1930s but ignored until racing companies began experimenting with them in the 1980s, DCTs have separate clutches for the even-numbered and odd-numbered gears. Because one set of gears is always in reserve, gear changes can occur faster than with a manual shift or a torque-converter-driven shift from a traditional automatic transmission. Porsche began using a DCT in 1983 in its 956 racecar. Race drivers shift DCT gears with paddle shifters on the steering column, a feature that has become popular in many mainstream cars. Lighter, less complicated, and more fuel-efficient than traditional automatic transmissions, DCTs are still fairly rare in production cars, though Ford uses the technology in its Focus compact.

CVT – In 1993, Great Britain’s Williams Racing replaced the traditional gearbox in its cars with a CVT – a transmission that uses offset pulleys to create the equivalent of gear ratios. Because the distance between the pulleys isn’t fixed, the transmission can find the most efficient ratio to transmit engine power to the wheels. The CVT was banned from F1 and did not make it into mainstream passenger cars for another decade when it became an option in General Motors’ Saturn VUE and Nissan’s Murano crossovers. Today, CVTs are common in some of the most popular cars on the road, including the Honda Accord.

1953 Jaguar C-type, the first racecar to use disc brakes.

Controls

Every time you pump up the volume in your car by flipping a thumb switch on the steering wheel, thank racecar drivers. Automotive human-machine-interface (HMI) designers study how many functions they can put at a driver’s fingertips by adding switches, paddles, and buttons to steering wheels by looking at how well the best drivers in the world handle such controls.

On the McLaren Honda Formula 1 wheel, drivers can use controls to:

Shift gears

Answer yes/no questions

Manage the differential

Manage hydraulics

Shift into neutral

Control energy recovery while braking

Call crew members

Display maps on wheel-mounted screen

Set tire conditions

Set braking sensitivity

Control chassis settings

Order a drink

Steer the car around the track

1993 Williams FW15C Formula 1 car, the first to use a continuously variable transmission (CVT).

Brakes

Rapidly reducing speed is as important to race drivers as powerful acceleration. The last driver to safely apply brakes when approaching sharp track turns can pick up a few seconds from competitors who had to brake early to play it safe. In the 1950s, that led to the racing development of disc brakes. Disc brakes use calipers to grab a disc attached to the wheel, using friction to slow the vehicle. They’re more responsive than older drum brakes that push brake shoes against the interior surface of a rotating cylinder.

In 1953, Jaguar fitted C-type racecars with disc brakes for the 24 Hours of Le Mans race in France. The car dominated the race, shattering track records for average lap speed, distance travelled on the 24-hour circuit, and margin of victory. Two years later, disc brakes began appearing in production cars. Most modern vehicles use disc brakes on the front wheels, the ones most responsible for handling, and drum brakes on the rear where loads are lighter.

Aerodynamics

Even at NASCAR, where racecars mimic passenger car designs, engineers spend countless hours in wind tunnels tweaking every surface to reduce drag. The goal is to boost performance and fuel economy (the car that skips one pit stop for refueling gains an edge over the less efficient).

In 1968, Lotus added airfoil wings to the front of its Model 49 Formula 1 car, for downforce to keep wheels glued to the track for better acceleration and braking. Within a few years, the giant spoilers that identify Formula 1 cars became the norm.

Modern car aerodynamic improvements focus on fuel economy. Several mainstream cars have recently adapted Formula 1-style active air management systems. Since the 2012 model year, the Chevrolet Cruze has had versions with active grille shutters that cut off airflow to the engine bay at higher speeds, reducing drag. In slower driving, the shutters open to cool the engine. Ford has added that technology to several cars, including the Mustang.

Steering wheel from a McLaren Honda Formula 1 car.

Materials

Automakers experimented with aluminum bodies on tracks long before using it on passenger cars. As consumer vehicles have added aluminum doors, hoods, and liftgates, racecars have abandoned steel frames for aluminum or magnesium components. Materials that lower weight, making it easier for the engine to throw the chassis around corners, are welcome on the track.

For the past decade, that has meant carbon fiber reinforced plastics (CFRP), composite materials that are as strong as steel at a tiny fraction of the weight. In 1981, McLaren built the MP4/1, a Formula 1 car with a CFRP chassis and monocoque body. At the time, the big question was how the material would perform in a catastrophic crash, with some critics claiming it would leave behind a black cloud of dust and a handful of metal components. McLaren answered that question when driver John Watson crashed at 150mph during a practice run in Italy. The engine and transmission were torn from the car, but the structure remained intact and Watson walked away from the wreckage.

CFRP has not yet become mainstream, but it can be found on high-performance cars such as Chevrolet’s Corvette ZR-1, Ford’s GT, or the Bugatti Chiron. The least-expensive vehicle to feature it is BMW’s i3 electric car, a vehicle that starts at about $45,000 before $7,500 in federal tax credits. Several materials companies are working to lower costs to make CFRP more viable.

More than just parts

Automotive designers get a lot more than car designs and technologies from racing, says Mark Kent, director of Chevrolet Racing at General Motors, responsible for the brand’s cars in NASCAR Monster Energy Cup, NASCAR Xfinity Series, and NASCAR Camping World Truck Series; Verizon IndyCar Series; NHRA, Pirelli World Challenge, and Corvette Racing in the International Motor Sports Association (IMSA); the 24 Hours of Le Mans; and the Cadillac Racing program in the Prototype Class of IMSA.

“When you look at technology transfer, there are three elements – improving the part itself, improving processes, and developing people,” Kent says. “There are processes that we develop for racing that make their way into our production vehicles.”

Racing processes – Racing designers have long had to plan for 200mph speeds, but production engineers did not have that problem – until recent Corvete models could approach those speeds.

“The production team came to the Corvette racing team for advice on how to test the car for performance at those levels,” Kent says. “We had some computational fluid dynamics (CFD) tools that could test the car at 200mph that the internal team did not. We transferred that technology to the production team, so they have the same tools now.”

A performance car such as the Corvette gains a lot of technology from the race world, but Kent says less power-focused vehicles have also benefitted – including one of GM’s most fuel-efficient vehicles.

“We developed a water pump for NASCAR. With NASCAR, we’re always looking for reliability and efficiency, so we designed something that fit those needs,” Kent says. “The same tools and processes for that NASCAR pump were used to create a water pump impeller for the Chevrolet Volt (plug-in hybrid).”

Even rules changes on the race circuit can filter into mainstream vehicles. Track rules have limited the amount of testing teams can do, so Chevrolet Racing engineers had to develop driver-in-the-loop/hardware-in-the-loop computation systems to simulate race conditions and component performance.

“Our production counterparts were trying to figure out what they wanted for a simulator,” Kent explains. “When they saw our system, they ended up adopting exactly what we were doing. They were on a different path, but they’ve converged with us. Now, we even share spare components on the simulators.”

Developing talent – Kent started at GM in motorsports in the 1980s, but later spent decades working on production vehicles and engines. He returned to racing in 2005.

“We try to identify up-and-coming engineers, and we give them a rotational assignment in motorsports,” Kent says. “It’s a very fast-paced environment, and there’s no better way to teach someone program management skills and decision-making skills. You become a bigger asset to the company and the production side after you’ve spent some time in motorsports.”

While the challenges are radically different – designing new parts for each race vs. designing a part that will remain unchanged for five years – Kent says, “I took that sense of urgency and the enhanced skills that I got from motorsports and took them into production. The skillset you need for racing is the same skillset you need for developing great street cars.”

Marketing – Car dealers still talk about “Win on Sunday, sell on Monday.” And while it’s harder to draw a straight line between sales performance and race wins, Kent says he’s sure there’s an impact.

“People sponsor football and other sports,” Kent explains. “But racing is the only one where the product is a car. And we sell cars and trucks.”